DEVICE FOR COMPACTING RETURNABLE PACKAGES

Abstract: The invention relates to a device for compacting recyclable packages, such as beverage cans or bottles, which comprises an infeed unit, a checking unit and a compacting unit. The novelty of the invention is that the compacting unit comprises a fixed, rigid wall (32), a movable, rigid wall (34) as well as means for displacing the movable wall (34) towards the fixed wall (32), the walls (32, 34) being substantially parallel also during the displacement of the movable wall (34) towards the fixed wall (32).

Description: DEVICE FOR COMPACTING RETURNABLE PACKAGES. The present invention relates to a device for com¬ pacting recyclable packages in general and beverage con¬ tainers, such as metal cans or so-called PET bottles, in a recycling system in particular. The consumption of beverages contained in metal cans and PET bottles has increased steadily in recent years, resulting e.g. in an increased strain on the environment, in that a considerable number of cans or bottles are not recycled but discarded after use. By using non-biodegradable aluminium in the beverage cans, long-term problems may arise. This also goes for certain plastics materials that are sometimes used in the manufacture of bottles for beverages. To protect the environment by recycling the base material, i.e. the aluminium or the plastic, recycling systems for this type of beverage containers have therefore been introduced. By including a deposit or refund in the sales price of aluminium cans and PET bottles, there is created an incentive to return the empty packages. On this occasion, a refund is made and the empty package enters the recycling procedure, in which the collected cans and bottles are transported to a depository for collection, smelting, etc. Efficient collection means, for instance, that the consumer is offered the opportunity to return beverage containers in several optional places. As a rule, this means that it should be possible to return the cans and bottles close to the point of sale, e.g. a supermarket, local shop, filling station or kiosk. Efficient collection also involves the use of effi¬ cient equipment for receiving beverage containers, i.e. cans or bottles, for handling the containers and for printing out a refund slip or paying out cash for the number of cans and bottles returned and accepted. Moreover, the returned packages are suitably compacted in the recycling apparatus itself or in equipment adjacent to it, since this will lengthen emptying intervals. Also, there is another potential problem to be considered, namely that the equipment used in the recycling system must be capable of verifying whether the packages returned are to be allowed into the recycling system or not. Even if a single aluminium can or plastic bottle represents but a limited economic value, it will be appreciated that many such cans or bottles represent a considerable such value. There is thus a risk that cans and bottles not intended for recycling will all the same be deposited into the recycling system. Besides, there is a risk of negligent behaviour or even attempted sabotage, e.g. by people putting glass or metal nails in the cans or bottles, or by people depositing packages which are not completely empty. The equipment to handle deposit¬ ed beverage containers must thus be capable of decid¬ ing whether the cans or bottles returned comply with a number of predetermined parameters, e.g. relating to refunding, package material, contents and so forth. From SE-B-420,135, for example, it is known to decide, by means of capacitive and inductive trans¬ ducers, whether a returned can is made of sheet metal or any other material. Depending on the measuring result, a conveyor is brought either into a first position, in which it communicates with compacting equipment, or into a second position, in which it com¬ municates with collecting container for rejected pack¬ ages. The drawback of this arrangement is that, although it is possible to distinguish between alu- minium cans and sheet-metal cans, it is not possible to detect the presence of foreign objects, such as glass and metal nails, or liquid remaining in the returned can. It is appreciated that such objects or remaining liquid may damage the compacting equipment and/or introduce unsuitable materials into the smelt¬ ing process. Moreover, this arrangement does not enable sorting out plastic deposit bottles. The stamp- type compacting equipment used in this context has proved unsuitable, since it requires a compressor, a pressure tank and several solenoid valves, which have turned out to be sensitive to interference. Many of the disadvantages referable to the prior art arrangement described in SE-B-420,135 have been solved by the arrangement described in SE-B—65,743. Instead of a conveyor, use is made of a motor-control¬ led cradle which, depending on the result from a num- ber of measurements, ejects a returned can either in a first direction or in a second direction, i.e. the can is either rejected or accepted and displaced to a compacting unit. After depositing, the can initially passes a metal detector, whereupon its length is measured during displacement from the deposit opening to the above-mentioned cradle. According to SE-B- 465,743, it is of great importance to establish the weight of the can to detect cans which, although con¬ sisting of an acceptable material, contain some type of foreign matter. The weight of the can is measured as a function of the moment of inertia occasioned by the can when the cradle is rotated. The compacting equipment is of the chain type, in which returned, accepted bottles are crushed and perforated. Although the arrangement according to SE-B- 465,743 solves some problems encountered in the art, new problems arise or old ones are not satisfactorily solved. Thus, it has been found quite complicated to establish the weight of the returned cans on the basis of the moment of inertia caused by the can during its displacement. Also, the measurements conducted have even proved to become incorrect under certain condi- tions, this resulting either in that a correctly rejected can is accepted or vice versa. Both the consumer and the operator of the recycling system must however be certain that cans intended for recycling and complying with a given, simple requirement profile can be returned against the payment of a refund, and that only such cans as comply with the requirement profile are accepted by the recycling system. Further, this arrangement, like the first-mentioned arrangement, has proved unsuited for handling plastic deposit bottles. An object of the present invention therefore is to provide a device for compacting recyclable pack¬ ages, such as aluminium cans or plastic bottles, in compliance with a certain, predetermined requirement profile. A second object of the present invention is to provide a device having a compact and robust as well as energy-efficient compacting unit. A third object of the present invention is to provide a device for compacting recyclable beverage containers, which has such a size and involves such costs and is so reliable that it can be employed also at minor points of sales, such as filling stations and kiosks. These and other objects are achieved by means of a device of the type stated in the introduction of this specification and having the features recited in appended claim 1. Variants and special embodiments are stated in the subclaims. An exemplary embodiment of the present invention will now be described with reference to the accompany¬ ing drawings. Fig. 1 is a side view of a device for compacting recycled beverage containers according to the present invention. Fig. 2 is a longitudinal section of the inventive device. Fig. 3 is a top view of the inventive device. Figs 1-3 show an embodiment of an inventive device 2 for sorting beverage containers, such as metal cans or plastic bottles (not shown), and subse¬ quent compaction of packages complying with a certain, predetermined requirement profile and thus qualifying as accepted packages. The device 2 has an infeed unit 4, a checking unit 6 and a compacting unit 8, which will be described in more detail hereinbelow. A returned can or bottle is deposited in the infeed unit 4, which has a space with a substantially vertical opening 10' and a substantially horizontal opening 10", below which there is provided a tubular element 14 which is rotatable about a substantially horizontal shaft 12 and having an internal diameter which slightly exceeds the external diameter of ordinary recyclable beverage cans or bottles currently existing on the market. In an initial position, one end of the tubular element 14 substantially connects with the substantially horizontal opening 10" of the above-men¬ tioned space. By limiting the size of the opening 10 and adapting the diameter of the tubular element 14, a first primary sorting is carried out of the objects to be deposited in the inventive device. Moreover, a metal detector 15 of inductive or capacitive type is arranged at the tubular element 15. Such detectors are well-known in the art and, therefore, will not be described in more detail here. Between the opening 10" and the upper end of the tubular element 14, there is provided a dividable bot¬ tom plate 16 obstructing or exposing the upper end of the tubular element 14 for reasons which will be stated below. In the substantially vertical, initial position of the tubular element 14, the lower end thereof is located just above a substantially horizon- tal, preferably rotating plate 18. The plate 18 is driven by a drive unit 20, i.e. a motor, which drives the plate 18, either directly or via a transmission means, such as a belt. In the illustrated embodiment, the plate 18 and the whole or parts of the drive unit 20 are suspended in pendulum fashion from a pin 22. A counterweight 24 is so adjusted as to balance the plate 18, the drive unit 20 and an aluminium can or plastic bottle accepted in accordance with the above- mentioned requirement profile, which is placed on the plate 18. Below the rotating plate 18, there is pro¬ vided, for example, a limit switch (not shown). When an object not complying with the requirement profile by having an excessive weight is placed on the plate 18, this is pivoted downwards so as to actuate the limit switch, which in turn entails that the tubular element 14 is rotated to a first end position, in which it makes an angle of e.g. +45° with the vertical plane, thus passing the object on to e.g. an ejector. The same things happens if a returned can does not comply with the requirement profile by being made of a non-accepted material. This is established by means of the metal detector 15, whence the measuring results are supplied to a central control unit, in turn actuating the tubular element 14 for rejecting the deposited can. However, when an aluminium can comply¬ ing with the requirement profile and accepted by the metal detector 15 is placed on the plate 18, the tubular element 14 is rotated after a certain prede- termined time period has elapsed, to a second end position, in which it makes an angle of e.g. -45° with the vertical plane, thus passing the object on to e.g. the compacting unit 8. In another embodiment, there is no counterweight 24, but the plate 18 comprises a load cell for establishing the weight of the load placed on the plate. However, the processing of the above-men¬ tioned signals nonetheless takes place in the afore- mentioned central control unit which is in the form of e.g. a microcomputer. As mentioned above, the plate 18 preferably is rotary. The reason for this is that there is provided beside the plate 18 a bar-code reader 26, which also is connected to the above-mentioned microcomputer. The bar-code reader is used for identifying a bar code which is applied on the can or the bottle and which may contain information about manufacturing/recycling country, type of package, size of refund and so forth. When the beverage container is deposited and passes through the tubular element 14, it will pass the metal detector 15 and land on the plate 18. While being weighed, the beverage container is turned by the rotating plate 18 past the reader 26 for establishing e.g. the type of package, i.e. whether the package is a metal can or a plastic bottle, the size of the refund etc., this information being stored in the microcomputer. The microcomputer activates the actuat- ing means 28 and 30 which rotate the tubular element 14 through an angular range of +45° and -45°, respec¬ tively. Thus, it is also possible to reject a returned can or bottle whose external characteristics comply with the predetermined requirement profile by reading the aforementioned bar code on the can returned. In this manner, it will be possible, for example, to use different refund amounts for different geographical areas or to direct the deposit of recyclable packages to a certain recycling place. As mentioned above, deposited but rejected pack¬ ages are conveyed e.g. to an ejector, which is achieved by the corresponding actuating means 28 caus¬ ing the tubular element 14, partly surrounding the returned can, to rotate approximately +45° about the substantially horizontal shaft 12. If the returned package is however accepted in all aspects, i.e. complies both with the physical, predetermined requirement profile and with the "soft" requirement profile sensed by the microcomputer by means of the bar-code reader, the accepted package is moved onwards by actuation of the corresponding actuating means 30 so as to rotate the tubular element 14 through -45°, to the compacting unit 8. In the illustrated embodiment, there is provided below the infeed and checking units 4 and 6 a shear¬ ing-type compacting unit. It essentially comprises a fixed rigid wall 32 and a wall 34 which is movable between substantially two end positions, in parallel with and towards the rigid wall 32, such that in a first end position it is located spaced from the rigid wall 32, the distance between the walls 32, 34 slightly exceeding the diameter of a can or bottle complying with the aforementioned requirement profile, while in a second end position it substantially makes contact with the rigid wall 32. In the illustrated embodiment, the displacement of the movable wall 34 is brought about by an eccentric/lever mechanism, see especially Fig. 1. A disc 36, rotatably mounted in its centre, is driven by a motor 38. In the edge region of the disc is rotatably fixed one end 48 of a transmis¬ sion arm 40, see especially Fig. 2, the other end of which is connected to one end of a lever 42 whose other end is connected to the movable wall 34. In the illustrated embodiment, one revolution of the disc 36 corresponds to a compacting motion of the compacting unit 8. Outside the edge region of the disc 36, there is provided a contact means 50 actuable by the trans¬ mission arm 40 and one end 48 thereof. The contact means 50 can be actuated by direct contact, for example being a microswitch, or be e.g. of magnetic type. The signal from the contact means 50 is supplied to the aforementioned microcomputer which, responsive to this signal, controls the opening and the closure of the dividable bottom plate 16, so that more than one can or bottle is never passed on to the compacting unit 8. As illustrated in Fig. 1, the other end of the lever 42 is displaced through a substantially quarter- circle-shaped path 44 when the transmission arm 40 is moved upwards. As the movable wall 34 during its dis¬ placement is parallel to the fixed wall 32,* it will be appreciated that a can or bottle located between the walls, and possibly supported by a bottom pin 46, see Fig. 2, is compacted in a shear motion, i.e. is crushed substantially in the longitudinal direction. This shear motion requires considerably less energy and force than other known compacting techniques. The present invention is intended for use in a recycling machine for refund-type beverage containers complying with a certain requirement profile. The invention is especially well suited for use in a small-size compactor in local shops, filling stations, kiosks and the like. The paying-out unit necessary for printing out refund slips or for paying out the refund is suitably connected to the aforementioned micro¬ computer, which calculates the amount to be refunded. It is understood that a person skilled in the art may find alternative embodiments and other means which bring about the technical effect aimed at and which fall within the scope of the inventive concept. All such alterations and modifications are therefore intended to be encompassed by the claimed scope of protection.

Claims: CLAIMS 1. A device for compacting recyclable packages, such as beverage cans or bottles, which comprises an infeed unit (4), a checking unit (6) and a compacting unit (8), c h a r a c t e r i s e d in that said com¬ pacting unit (8) comprises a fixed, rigid wall (32), a movable, rigid wall (34), and means for displacing the movable wall (34) towards the fixed wall (32), said walls (32, 34) being substantially parallel also during the displacement of the movable wall (34) to¬ wards the fixed wall (32). 2. A device as claimed in claim 1, c h a r a c - t e r i s e d in that the maximum distance between the fixed wall (32) and the movable wall (34) is slightly greater than the diameter of a deposited can or bottle complying with a requirement profile, and that the movable wall (34) executes a quarter-circle-shaped movement, so that the package located between the walls (32, 34) is compacted by a shear movement. 3. A device as claimed in claim 1 or 2, c h a r a c t e r i s e d in that the movable wall (34) is displaced by means of a lever mechanism (42), one end of which is connected to the movable wall (34) and the other end of which is connected to one end of a transmission arm (40) whose other end is movably con¬ nected to the edge region of a rotating disc (36), so that one revolution of the rotating disc (36) cor- responds to one stroke of the compacting unit (8). 4. A device as claimed in claim 3, c h a r a c ¬ t e r i s e d in that a detector (50), upon the pas¬ sage of said other end of the transmission arm (40), generates a signal which is fed to a control means which, responsive to this signal, opens or closes an upper opening (16) in a tubular element (14) in the infeed unit (4). 5. A device as claimed in claim 4, c h a r a c ¬ t e r i s e d in that said tubular element (14) is substantially cylindrical and having one end facing the infeed unit (4) and the other end facing the checking unit (6), and that it is connected to means (12, 28; 30) for moving the tubular element (14) between different end positions in dependence upon signals (6) fed to said control means. 6. A device as claimed in claim 5, c h a r a c - t e r i s e d in that the tubular element (14) is pivotable through about +45° from the initial position to a first end position, in which rejected beverage containers are moved to an ejection port, and pivotable through about -45° from the initial position to a second end position, in which accepted beverage containers are moved to the compacting unit (8). 7. A device as claimed in any one of claims 1-6, c h a r a c t e r i s e d in that said checking unit (6) comprises a metal detector (15) integrated with the tubular element (14) extended substantially in the vertical direction, and a load cell or counterweight, connected to a substantially horizontal plate (18), for detecting the weight of a beverage container located on the plate (18) and generating a signal which is fed to said control means, as well as a bar¬ code reader (26) disposed above the plate (18) and generating a signal which is also fed to said control means. 8. A device as claimed in claim 7, c h a r a c - t e r i s e d in that said plate (18) is mounted in pendulum fashion on a pin (22) and, at a certain deflection from a substantially horizontal normal position, acts on a detector which generates a signal in response thereto.

Inventors: BERTRAM LARS, BERTRAM, LARS
Applicants: BERTRAM LARS, SCANMATIC AB, BERTRAM, LARS
Application year: 1994
Main classification: G07F7
IPC codes: B30B9, G07F7